1. Field of the Invention
In general, the present invention relates to portable cutting machines that are used to cut grooves in paved surfaces. More particularly, the present invention relates to cutting machines that are used to cut away loose material from in and around cracks that may be present in the paved surface.
2. Prior Art Description
Many surfaces, such as streets, parking lots, driveways and the like are paved either in asphalt or concrete. Over time, cracks have a tendency to develop in the pavement material. As cracks develop, water is able to seep deeper and deeper into the pavement material. As the water, repeatedly freezes and thaws, the water expands the crack. This increases the size of the cracks, thereby letting even more water and dirt into the cracks. Once dirt is present in a crack, seeds can take root in the cracks. The roots of growing plants further increase the size and number of cracks, thereby letting more and more water, dirt and seeds into the pavement. Eventually, the prevalence and severity of the cracks become so pronounced that the integrity of the paved surface is compromised. Once so damaged, the paved surface cannot be economically repaired. The paved surface must, therefore, be either replaced or buried under a new paved surface.
In order to prevent a paved surface from becoming damaged, maintenance must be periodically performed on the paved surface. One of the most common and useful maintenance procedures is crack repair. During crack repair, the cracks in a paved surface are sealed. In this manner, water, dirt and seeds are prevented from entering the crack and degrading the paved surface. Small cracks can be sealed simply by covering the crack with tar or liquefied asphalt. However, larger cracks are often filled with dirt, leaves, gravel and other debris. These larger cracks must be cleaned of this debris before they can be properly sealed.
Each contractor has a preferred method of cleaning out large cracks in paved surfaces. For instance, some contractors rely upon manual labor and have men armed with pneumatic chisels manually clean large cracks. This technique produces good results, but is very time consuming and labor intensive. In attempts to make crack cleaning more efficient, motorized saws are sometimes employed. In the prior art, there are many portable motorized saws that are used to cut groves into a paved surface or asphalt or concrete. These saws typically have a round rotating blade that can be lowered into the paved surface as the saw is moved along the paved surface. Such motorized saws are designed to cut straight lines in pavement and are usually used to make stress relief joints and other long, straight cuts.
When such a motorized saw is used to clean a pavement crack, many problems occur. One big problem is that cracks rarely run straight. A saw must therefore constantly be turned in direction as it follows a crack. With many prior art saws, the saw blade must be lifted out of the pavement, the saw turned to a new direction, and the saw blade replunged into the pavement each time the motorized saw changes direction. If the saw is turned with the blade in the pavement, the saw blade can bind and/or break.
Another problem associated with pavement cracks is that pavement cracks vary in width and depth from point to point along the length of the crack. If a prior art motorized saw is used, the saw blade must be constantly adjusted in cut depth to avoid excessive wear. Furthermore, a blade thicker than the widest part of the crack must be used to ensure the blade fully cleans the crack. This causes the blade to cut far more material than is required in most parts of the crack. This results in excessive wear to the blade and greatly decreases the life of the blade.
A need therefore exists for a pavement cutting machine that is specifically designed to follow and clean pavement cracks, wherein the cutting machine avoids the disadvantages of prior art cutting machines that have been previously mentioned.